| Author | Topic |
|---|
Registered:
June 2002
|
|
PD superchargers, tech Q's
|
Wed, 10 December 2003 02:56
|
 |
All right, how would one calculate (roughly, not to 10dp's) how much boost a PD supercharger would run on a certain engine??
Is it directly related to the ratio between then CFM of the SC to the CFM of a NA engine at a given RPM??
eg.if an engine sucked 400cfm at 3000rpm and the supercharger pushed 600cfm thus giving a ratio of (600-400)/400=0.5, does that equate to 0.5*1bar=0.5bar above gauge pressure(1.5bar absolute)??
Someone fill me in!!
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: PD superchargers, tech Q's
|
Wed, 10 December 2003 03:18
|
|
Yes, ignoring factors like pumping losses and thermal expansion that's pretty much how it works. 
|
|
|
Registered:
June 2002
|
|
Re: PD superchargers, tech Q's
|
Wed, 10 December 2003 03:47
|
|
Thanks for the prompt reply Norbie.
Who knows what cfm SC14 flows?? and what RPM is that at??
Norbie/others, is there a loss factor that can be applied as RPM increases, to get a rough idea?
I can't imagine it being exactly linear from say 100cfm@1000rpm to 700cfm@7000rpm for example.
|
|
|
Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
|
|
Re: PD superchargers, tech Q's
|
Wed, 10 December 2003 04:00
|
|
i believe the SC14 has a capacity of 1.4L/rev... anyone else?
there wil be some loss due to heating, but since it is positive displacement, and it is drawing in cold air, they will not be huge.. not compared to a turbo anyways..
problem is that it heats up the air as it leaves the SC, so the motor itself doesn't draw in as much air, altho the manifold pressure is higher since the heated air expands etc etc..
Cya, Stewart
|
|
|
Location:
Perth
Registered:
July 2002
|
|
Re: PD superchargers, tech Q's
|
Wed, 10 December 2003 04:55
|
|
Max revs for the SC14 is supposed to be about 9000 rpm for the best efficiency.
Actual swept volume of the sc14 is 1420cc
|
|
|
Registered:
June 2002
|
|
Re: PD superchargers, tech Q's
|
Wed, 10 December 2003 20:00
|
|
|
Thanks guys.
|
|
|
